Merge pull request #2730 from celeron533/plugin_not_found

Give a more user friendly message when plugin program file does not exist

shadowsocks-csharp/Controller/Service/Sip003Plugin.cs

@@ -100,7 +100,22 @@ namespace Shadowsocks.Controller.Service
                 _pluginProcess.StartInfo.Environment["SS_LOCAL_HOST"] = LocalEndPoint.Address.ToString();
                 _pluginProcess.StartInfo.Environment["SS_LOCAL_PORT"] = LocalEndPoint.Port.ToString();
                 _pluginProcess.StartInfo.Arguments = ExpandEnvironmentVariables(_pluginProcess.StartInfo.Arguments, _pluginProcess.StartInfo.EnvironmentVariables);
-                _pluginProcess.Start();
+                try
+                {
+                    _pluginProcess.Start();
+                }
+                catch (System.ComponentModel.Win32Exception ex)
+                {
+                    // do not use File.Exists(...), it can not handle the scenarios when the plugin file is in system environment path.
+                    // https://docs.microsoft.com/en-us/windows/win32/seccrypto/common-hresult-values
+                    //if ((uint)ex.ErrorCode == 0x80004005)
+                    //  https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-erref/18d8fbe8-a967-4f1c-ae50-99ca8e491d2d
+                    if (ex.NativeErrorCode == 0x00000002)
+                    {
+                        throw new FileNotFoundException(I18N.GetString("Cannot find the plugin program file"), _pluginProcess.StartInfo.FileName, ex);
+                    }
+                    throw new ApplicationException(I18N.GetString("Plugin Program"), ex);
+                }
                 _pluginJob.AddProcess(_pluginProcess.Handle);
                 _started = true;
             }

shadowsocks-csharp/Data/i18n.csv

@@ -187,6 +187,7 @@ Proxy handshake failed,代理握手失败,Proxy 交握失敗,プロキシ ハン
 Register hotkey failed,注册快捷键失败,註冊快速鍵失敗,ホットキーの登錄に失敗しました。
 Cannot parse hotkey: {0},解析快捷键失败: {0},剖析快速鍵失敗: {0},ホットキーを解析できません: {0}
 "Timeout is invalid, it should not exceed {0}",超时无效，不应超过 {0},逾時無效，不應超過 {0},タイムアウト値が無効です。{0} 以下の値を指定して下さい。
+Cannot find the plugin program file,找不到插件程序文件,找不到外掛程式文件,,
 ,,,
 Operation failure,操作失败,,
 Auto save failed,自动保存失败,,